Process of manufacture of slide fastener elements



0a. 27, 1942. R J; SMITH AL 2,299,936

PROCESS OF MANUFACTURE OF SLIDE FASTENER ELEMENTS Filed Feb. 20, 1939 ATTORNEY Patented Oct. 27, 1942 PROCESS OF MANUFACTURE OF SLIDE FASTENER ELEMENTS Roscoe J. Smith, Glen Ridge, N. J., and Abraham B. Schachat, New York, N. Y.

Application February 20, 1939, Serial No. 257,442

3 Claims.

It is an object of our invention to provide a very eflicient method or process for the manufacture of slide fastener elements or scoops. Heretofore, these elements have been manufactured by various processes which are wasteful of the raw material or stock out of which the elements are formed. This waste is sometimes as high as 60% of the material used, while in our process a very small percentage of waste obtains. We also desire to provide a process which will adapt itself to a continuous element and tape assembly method, as disclosed in our co-pending application, Serial No. 235,963.

A further object of our invention is to disclose and teach a process of making slide fastener elements or scoops whereby different kinds of materlals may be used, and during the process a stock or strip can be Plated, enameled, coated, or otherwise processed for the final assembly of the elements on the carrier tape. Also, the scoops produced in accordance with our process will make it possible to assemble the elements on to the tapes at very much higher speeds than have heretofore been possible. It is obvious also that our elements will not have, any sharp edges or burrs, which are all eliminated, thus providing a smoothly operating slide fastener after the assembly of the elements on the tape.

Our invention will be more readily understood by reference to the accompanying drawing, in which like numbers refer to like parts in the several views.

Figure 1 is a diagrammatic illustration of a plan view of the strip in process.

Figure 2 is a diagrammatic side elevation of the strip in process.

Figure 3 is a section along the plane (33) of Figure 1.

Figure 4 is a section along the plane (4-4) of Figure 1.

Figure 5 is an enlarged plan view of one element or scoop.

Referring to the drawing, at l is illustrated a relatively thin and narrow sheet of strip material, which passes into a shearing step at 2 as illustrated. The two portions of the strip now connected are separated as at X of Figure 1, and at the same time, they are placed at different planes, one with respect to the other. as illustrated at X in Figure 2. This assures that the individual elements are completely separated, one or the other. The strip then passes along where at 3 there is a cavity formed and simultaneously a lip 4. The strip then passes along to 5 where a trimming operation removes all burrs. The next step is illustrated at '6 where burnishing or swaging takes place, the better to smooth the elements. At I is illustrated the step of trimming the legs so as to form a relative curvature 9 shown in Figure 5. It will appear that the elements have now reached the shape and form illustrated in Figure 5, although still part of two continuous strips. At 8 is indicated a point where these two strips are run into cutting machines where the elements are cut and simultaneously the leg portions bend down with respect to the cavity 3 and lip 4, and thus formed into a position to be fed onto a tape, one preferred embodiment of which is described and claimed in our said co-pending application, Serial No. 235,963.

It must also be understood that we may cut off the individual elements from the stock or strip and bend the same and feed the same thus finished elements into a hopper or head suitable for any type of conventional slide fastener assembly machine so that the elements may thus be secured to or mounted on the tape from a hopper type machine. Notwithstanding, our process and method lends itself to assembly on the tape directly from the strip or stock if desired.

Having thus described our process, what we claim and desire to secure by United States Letters Patent is:

- and lips, trimming, burnishing and forming the element legs, said scoops or elements being in final form to be positioned on the carrier tape by cutting same from the element carrying stock just prior to said positioning on said tape.

3. A process of making slide fastener elements consisting of shearing a plurality of element forms simultaneously from a common relatively thin carrier stock, forming conventional cavities, trimming, burnishing and forming the element legs, said initial shearing operation being followed by the process of separating the two portions corresponding to the two sets of elements of the stock material in a horizontal and vertical plane.

ROSCOE J. SMITH. ABRAHAM B. SCHACHAT. 

